Skid steer loaders are well knows ground working machines that have hydraulically driven wheels that are fixed for rotation relative to the frame of the machine. Steering is accomplished by controlling the rotation of the wheels on opposite sides of the machine such that a differential in rotational speeds will result in a turning of the machine. The skid steer loader has a centrally positioned operator compartment mounted on the frame with an engine typically located behind the operator. A pair of boom arms is pivotally supported on the frame for vertical movement on opposite sides of the operator compartment. These boom arms are connected together forwardly of the operator compartment with an attachment plate through which various attachments can be mounted to the boom arms.
Skid steer loaders are manufactured in many sizes for use in a variety of operations from cleaning chicken houses to moving materials from one location to another. Because of the versatility of skid steer loaders many attachments have been devised for mounting on the boom arms forwardly of the operator to accomplish the desired operation for the skid steer loader. One simple such attachment is a loader bucket that has a mechanism along the rearward wall to permit connection with the attachment plate and is then operable to scoop materials, such as feed for animals, with the forward movement of the machine and to elevate those materials by vertically moving the boom arms. Hydraulic cylinders controllable by the operator allow the bucket to rotate about a pivot axis to tip the bucket in order for the materials to spill out of the bucket.
Devices for defacing and removing compacted silage material placed into bunkers are known in the art. In U.S. Pat. No. 6,841,322 granted on Nov. 9, 2004, to Kenneth Slabey, a bunk defacer is mounted on a skid steer loader and is hydraulically powered from the auxiliary hydraulic system of the skid steer loader. The bunk defacer is mounted on the boom arms of the skid steer loader and is movable vertically by moving the boom arms. In an earlier U.S. Pat. No. 5,495,987 granted on Mar. 5, 1996, to Kenneth Slabey, this bunk defacer is shown mounted to the boom arms and cooperable with a loader bucket to load a quantity of the forage material into the bucket for transport away from the silage bunker.
In U.S. Pat. No. 4,157,164, granted to Arnold Helm, et al on Jun. 5, 1979, a self-propelled forage harvesting machine is equipped with a bunk defacer rotor supported on the distal end of boom arms to disintegrate the face of compacted silage material for feeding into the forage harvesting machine. U.S. Pat. No. 3,335,888, issued on Aug. 15, 1967, to Henry Kugler, discloses a silage loader in the form of a belt conveyor that includes teeth that deface the front surface of compacted silage in a bunker, and loads the disintegrated silage into a loader bucket mounted on a tractor. The conveyor belt is hydraulic driven and is positionably supported on the loader bucket.
In U.S. Pat. No. 3,779,408, issued to Louis Ivie on Dec. 18, 1973, a bunk defacer is pivotally mounted on the boom arms of a tractor-mounted bucket loader and is operable to be moved vertically to disintegrate compacted silage material and load the disintegrated material into the loader bucket beneath the bunk defacer apparatus. The bunk defacer is hydraulically driven from the tractor's hydraulic system and is provided with a separate hydraulic lift system to cause pivotal movement thereof. The bunk defacer apparatus in U.S. Pat. No. 3,847,266, granted on Nov. 12, 1974, to Celbert Cox, is pivotally mounted on top of a belt conveyor mechanism such that the bunk defacer rotor dislodges silage material that is collected in a lower collection bucket and is elevated and transported rearwardly by the belt conveyor. The bunk defacer rotor is supported on a frame assembly that includes a four bar linkage that not only moves the rotor vertically, but also extends the rotor longitudinally.
It would be desirable to provide a combination loader bucket and bunk defacing apparatus in which the bunk defacer could be retracted into the confines of the loader bucket when not being utilized to dislodge compacted silage material from the front face of a silage bunker. Preferably, the loader bucket would be attachable to a skid steer loader or any other loader apparatus providing an auxiliary supply of hydraulic fluid under pressure.